The present invention relates to methods for detecting an optimum recording bias in a magnetic recording and reproducing device. More particularly, the invention relates to a method for automatically detecting the optimum value of a recording bias in a two-head system tape recorder.
In a tape recorder, selection of the optimum recording bias is essential because the frequency characteristics and the harmonic distortion of a recording are greatly affected by the recording bias current value. It is necessary to provide different optimum recording biases for different types of magnetic tapes. Furthermore, since even magnetic tapes of the same type have different recording and reproducing sensitivities, it is difficult to make the frequency characteristics flat for all magnetic tapes.
Accordingly, an object of this invention is to provide a method for detecting an optimum recording bias in two-head system tape recorder in which the recording bias is automatically adjusted so that a flat frequency characteristic is provided for tapes of various types.